Dag

DAG stands for Directed Acyclic Graph. It is a graph, a set of nodes and links between nodes, that has very special properties. Ethereum uses a DAG in Ethash, the Ethereum Proof of Work (POW) algorithm.The Ethash DAG takes a long time to be generated, which is done by a Miner node into a cache file for each Epoch. The file data is then used when a value from this graph is required by the algorithm.